Well bow poundage is just one aspect. Your draw length is just as important when it comes to knowing the power level your bow is generating. That said, if you use the proper broadhead you can kill deer with a 40 lb bow out to 35 yards easily. With a 50 or 60 lb bow and the right broadhead you can kill them as far as you can reliably stick an arrow in their vitals. It is not hard for example to get good consistently lethal penetration on deer with two blade cut on contact style broadheads even from pretty low poundage bows.